English

Non-uniformly continuous nearest point maps

Functional Analysis 2024-02-08 v1 Metric Geometry

Abstract

We construct a Banach space satisfying that the nearest point map (also called proximity mapping or metric projection) onto any compact and convex subset is continuous but not uniformly continuous. The space we construct is locally uniformly convex, which ensures the continuity of all these nearest point maps. Moreover, we prove that every infinite-dimensional separable Banach space is arbitrarily close (in the Banach-Mazur distance) to one satisfying the above conditions.

Keywords

Cite

@article{arxiv.2402.04747,
  title  = {Non-uniformly continuous nearest point maps},
  author = {Rubén Medina and Andrés Quilis},
  journal= {arXiv preprint arXiv:2402.04747},
  year   = {2024}
}

Comments

14 pages, 1 figure

R2 v1 2026-06-28T14:41:24.448Z